Thursday, August 21, 2008

JBoss Profiler 2.0 Plugin for JON

I just started create a JON-plugin based on actual MBean that is the controller for execute the profiler commands, basically what I am doing for now is just "declare" the Services and Actions based on JMX-Actions, take a look on the actual result:

In addition, the Profiler Actions, I will be working a little bit more, when I get it done I will commit and create a distro into JBoss Profiler web site:

We are promoting a lot JON and RHQ-Project in Brazil, for many customers, JON is a good answer for an "Enterprise JBoss Management", if you have some MBeans ready that are really important for your Application, you can manage them using RHQ or JON much better than if you try do just using the legendary JMX-Console. Basically I did an rhq-plugin.xml describing my MBeans, see the following code:

For more information in how create Plugins for RHQ/JON:
  • http://support.rhq-project.org/display/RHQ/RHQ+Plugin+Community
  • http://support.rhq-project.org/display/RHQ/Writing+Custom+Plugins
Here some others screenshots:

New Commands available

Some Metrics, in a near future we will have profiler's reports available here

Installing, testing and Using JBoss Profiler 2.0 - beta2

This entry will show how start use the jboss-profiler beta2, first of all , download the software from here:
http://www.jboss.org/downloading/?projectId=jbossprofiler&url=/jbossprofiler/downloads/jboss-profiler-2.0.Beta2.tar.gz , save in some folder in your disk and unzip it.

Once you have the files in your disk, basically to setup jboss-profiler you will have to do the following steps:
  1. Copy jboss-profiler.jar to jbossas/bin
  2. Copy jboss-profiler.properties to jbossas/bin
  3. Edit jboss-profiler.properties in jbossas/bin to include the classes to be profiled
  4. Copy jboss-profiler-plugins.jar to jbossas/bin
  5. Edit run.conf (Unix) or run.bat (Windows) in jbossas/bin to include JBoss Profiler in JAVA_OPTS ( See you run.conf and add use this example: JAVA_OPTS="-javaagent:jboss-profiler.jar -Djboss-profiler.properties=jboss-profiler.properties -Xms128m -Xmx512m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000")
  6. Copy also to jbossas/bin the javaassist.jar if you are using JBoss AS 4.2.x
  7. Copy jboss-profiler.sar to jbossas/server//deploy
  8. Boot application server, if the following log appears everything is ok:
========================================================================= JBoss Bootstrap Environment JBOSS_HOME: /opt/java/jboss/profiler/as JAVA: /opt/java/jdk1.6.0_03/bin/java JAVA_OPTS: -Dprogram.name=run.sh -server -javaagent:jboss-profiler.jar -Djboss-profiler.properties=jboss-profiler.properties -Xms128m -Xmx512m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Djava.net.preferIPv4Stack=true CLASSPATH: /opt/java/jboss/profiler/as/bin/run.jar:/opt/java/jdk1.6.0_03/lib/tools.jar ========================================================================= JBoss Profiler 2.0.Beta2 (Sun Microsystems Inc. 1.6.0_03) JBoss Profiler depends on external communication module 10:55:51,681 INFO [Server] Starting JBoss (MX MicroKernel)... 10:55:51,707 INFO [Server] Release ID: JBoss [Trinity] 4.2.2.GA (build: SVNTag=JBoss_4_2_2_GA date=200710221139)

Profiling your Application with JBoss Profiler beta2

In order to show the testing, I will do some profiler in JBPM classes, just to check what is happening behind the scenes. To do that I have to edit the jboss-profiler.properties in jbossas.bin directory to add the reference for JBPM's classes, as which is: org.jbpm.* (includes=org.jbpm.*).

Actually JBoss Profiler uses JMX and MBeans as its infrastructure which allows you profiler either JBoss 4.2.x or future 5.x versions. When you deploy the .sar file, you can see the profiler in the jmx-console as you can see in the following image:

You can do several options using the commands via JMX-Console, or as well as you can use command-line interface. At this moment we will use the JBoss profiler CLI, so go to jboss-profiler2-beta-2-folder/ in your shell (Unix or Win) and type the following command: java -jar jboss-profiler-client.jar , the result will be the following:

[jsilva@jsilva jboss-profiler-2.0.Beta2]$ java -jar jboss-profiler-client.jar
Usage: Client [-h host] [-p port]
startProfiler : Start the profiler
stopProfiler : Stop the profiler
snapshot : Take a snapshot
getSnapshot : Get a snapshot
listSnapshots : List snapshots
clearSnapshots : Clear snapshots
gc : Trigger garbage collection
enable : Enable the profiler
disable : Disable the profiler
load : Load a snapshot
save : Save a snapshot
diff : Difference between snapshots
add : Add classes (repository must be enabled)
remove : Remove classes (repository must be enabled)


As far you can see you have all these options to invoke profiler operations, for testing I used the following:

1- java -jar jboss-profiler-client.jar snapshot - Which generated a snapshot.
2-java -jar jboss-profiler-client.jar listSnapshots - Which shows all snapshots I had taken from my App Server.
[jsilva@jsilva jboss-profiler-2.0.Beta2]$ java -jar jboss-profiler-client.jar listSnapshots
1: 21 August 2008 11:23:54:296 -> 21 August 2008 11:24:17:117
2: 21 August 2008 11:39:05:687 -> 21 August 2008 11:39:31:255
3: 21 August 2008 11:41:59:145 -> 21 August 2008 11:43:25:691

3- java -jar jboss-profiler-client.jar getSnapshot 3 - Which tells to my client flush in my disk the info about my snapshot number 3, after this if you type a ls (dir for win), you can see the folder with thesnapshot timestamp. Please enter on this folder and list the files and folders again, the results would be something like:

[jsilva@jsilva 20080821114159145-20080821114325691]$ ls
caller classes classes.txt hotspots.txt methods.txt overview.txt packages.txt threads


On the files above you can see the information about your classes, in my case, I just did some operations with my simple bpm application. Take a look on the overview.txt report content:

From: 21 August 2008 11:41:59:145
To : 21 August 2008 11:43:25:691

Threads:
========
Thread-60 20063.47 ms

Most time:
==========
Count Ms % Method
1 13453.22 67.05 org.jbpm.persistence.db.DbPersistenceServiceFactory#getSessionFactory()
1 6078.74 30.30 org.jbpm.db.hibernate.HibernateHelper#createConfiguration(String, String)
3 134.04 0.67 org.jbpm.configuration.ObjectFactoryImpl#getObject(org.jbpm.configuration.ObjectInfo)
6 116.03 0.58 org.jbpm.configuration.ObjectFactoryImpl#loadClass(String)
1 84.82 0.42 org.jbpm.persistence.db.DbPersistenceServiceFactory#openService()
1 79.14 0.39 org.jbpm.persistence.db.DbPersistenceServiceFactory#getConfiguration()
1 56.08 0.28 org.jbpm.persistence.db.StaleObjectLogConfigurer#wrap(org.apache.commons.logging.Log)
14 29.55 0.15 org.jbpm.calendar.Day#(String, java.text.DateFormat, org.jbpm.calendar.BusinessCalendar)
24 4.53 0.02 org.jbpm.calendar.Holiday#(String, java.text.DateFormat, org.jbpm.calendar.BusinessCalendar)
2 3.51 0.02 org.jbpm.calendar.Holiday#parseHolidays(java.util.Properties, org.jbpm.calendar.BusinessCalendar)

Hotspots:
=========
Count Ms Avg % Method
1 13453.22 13453.22 67.05 org.jbpm.persistence.db.DbPersistenceServiceFactory#getSessionFactory()
1 6078.74 6078.74 30.30 org.jbpm.db.hibernate.HibernateHelper#createConfiguration(String, String)
1 84.82 84.82 0.42 org.jbpm.persistence.db.DbPersistenceServiceFactory#openService()
1 79.14 79.14 0.39 org.jbpm.persistence.db.DbPersistenceServiceFactory#getConfiguration()
1 56.08 56.08 0.28 org.jbpm.persistence.db.StaleObjectLogConfigurer#wrap(org.apache.commons.logging.Log)
3 134.04 44.68 0.67 org.jbpm.configuration.ObjectFactoryImpl#getObject(org.jbpm.configuration.ObjectInfo)
6 116.03 19.34 0.58 org.jbpm.configuration.ObjectFactoryImpl#loadClass(String)
14 29.55 2.11 0.15 org.jbpm.calendar.Day#(String, java.text.DateFormat, org.jbpm.calendar.BusinessCalendar)
2 3.51 1.76 0.02 org.jbpm.calendar.Holiday#parseHolidays(java.util.Properties, org.jbpm.calendar.BusinessCalendar)
1 1.35 1.35 0.01 org.jbpm.util.XmlUtil#parseXmlInputSource(org.xml.sax.InputSource)

Allocations:
============
org.jbpm.db.hibernate.StringMax 149
org.jbpm.db.hibernate.ConverterEnumType 49
org.jbpm.configuration.AbstractObjectInfo 32
org.jbpm.calendar.Holiday 24
org.jbpm.calendar.Day 14
org.jbpm.configuration.FieldInfo 9


Conclusion

JBoss Profiler 2 is built on top of really cool technologies, such as JBoss AOP and JavaAssist, feel you free to contribute with bug-fixes, documentation or with whatever you think could be valuable for the project, it would be a great chance for joining at a JBoss Project as a contributor, as far the actual contributors: Jesper Pedersen, Clebert Succonic and I are not dedicated as a full-time developers for Profiler, the work you can see as the result is a really big effort that Jesper and Clebert are doing. Beyond simple CLI interface, we are planning 2 really cool news, one of that is a new JBoss Profiler console based on RichFaces and related technologies, besides a Plugin for JBoss Operations Network/RHQ Project as well.

Visit: http://www.jboss.org/jbossprofiler/

Monday, August 4, 2008

RESTEasy+jBPM: A Proof of Concept for a Process Server

This is a post where I will try share some thoughts about where REST could be useful inside a SOA architecture based on Open Source Technologies using REST and Business Process Management, in that case we will be using jBPM and RESTEasy, which is the JBoss's implementation for JSR311- Java Restful WebServices.


RESTEasy

RestEasy is a project that is getting a good relevance in terms of integration with some projects inside JBoss.ORG and even other projects. If you are trying use a simple REST implementation you should take a look on this projects, basically there are few steps you must to do to put RestEasy working for your Application, so see the following Steps:
  1. Download the RESTEasy from JBoss.ORG

  2. There is a worth documentation in RESTEasy Wiki, which I strongly recommend you read it first, in addition to this, in order to see some foundation for practical REST application, you can read this great blog entry written by Carol McDonald

  3. To make the things works, I recomend you read this link: http://wiki.jboss.org/wiki/RESTeasyInstal, RESTEasy is pretty easy to understand and apply in even legacy Java applications, where you can expose some methods simply putting some annotations into your pojos. Basically the steps are:
  • RESTeasy is deployed as a WAR archive and thus depends on a Servlet container. When you download RESTeasy and unzip it you will see that it contains an exploded WAR. Make a deep copy of the WAR archive for your particular application. Place your JAX-RS annotated class resources and providers within one or more jars within /WEB-INF/lib or your raw class files within /WEB-INF/classes. RESTeasy is configured by default to scan jars and classes within these directories for JAX-RS annotated classes and deploy and register them within the system:

Custom configuration

RESTeasy is implemented as a ServletContextListener? and a Servlet and deployed within a WAR file. If you open up the WEB-INF/web.xml in your RESTeasy download you will see this:


<web-app>
<display-name>Archetype Created Web Application</display-name>
<context-param>
<param-name>resteasy.scan</param-name>
<param-value>true</param-value>
</context-param>

<listener>
<listener-class>org.resteasy.plugins.server.servlet.ResteasyBootstrap</listener-class>
</listener>

<servlet>
<servlet-name>Resteasy</servlet-name>
<servlet-class>org.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>Resteasy</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>

</web-app>


The ResteasyBootstrap listener is responsible for initializing some basic components of RESTeasy as well as scanning for annotation classes you have in your WAR file. It receives configuration options from <context-param> elements. Here's a list of what options are available

  • And that's all! Everything you need is ready to run your REST
    Services in any JEE App Server.



Proof of Concept of a “Process Server”

We have several open source BPM Engines , I am using JBoss jBPM because I wanna show you a Web-Console where the process are running on, in addition a graphical tool to design my processes.
First of all I have a really simple “Controller” based on REST principles, nothing too complex or beautiful so far, but is useful, so I created a simple class called RestService.java where you can find many useful methods to operate business process using jBPM. Based on my own experience could be considered a “best practice” you design your URLs first, who knows some day we could create a tool (ant or maven), that could based on a text file containing one URL per line, where after reading it could create an abstract class with the methods. (Maybe a good way to forget any XML). Based on this practice I wanna give the ability for PHP, .net or even HTML interact with my “Process Server”, to do that I canhave the following URLs:
  1. /start/process/{some
    process}/{some user to be associated to my Swilanes}, it I can pass
    via a GET method and I can keep the process id as my return

  2. /signal/process/{the process id I
    must have stored somewhere}/{user} , via a GET I can navigate into
    my process

  3. /process/{process id}/add/var ,
    via a GET I can get a way to add some variables for my process
    execution

    Based on these 4 actions I defined above, I can show you now how implement them:


1- Start a new Process Instance

  • For jBPM you must have access to Context, which is the key object to operate processes using jBPM.

  • The following code shows this method in action:

@GET

@Path("/start/process/{processdefinition}/{user}")


@ProduceMime("text/plain")


public
String startProcesInstance(


@PathParam("processdefinition")String
processDefintion,


@PathParam("user")String
user) {


JbpmContext
ctx = JbpmConfiguration.getInstance().createJbpmContext();


try
{


ProcessInstance
instance = ctx.newProcessInstance(processDefintion);


instance.getContextInstance().setVariable("user",
user);


Token
t = instance.getRootToken();


t.signal();



ctx.save(instance);





return
new
Long(instance.getId()).toString();


}


catch
(Exception e) {


e.printStackTrace();


}


finally
{


ctx.close();


}


return
"ERROR";



2 - Signaling your Process

Once you have your Process Id, you can operate it and do whatever you want, this is one of the “Key-benefits” in jBPM, the ability to keep everything related to the process stored in the database, and not in the memory, it allow you have several application interacting with your Process Engine, for my testing, I have jBPM Server (jBPM+JBoss [could be any other AppServer]) in one IP address, and a TomCat with my simple REST application based in RESTEasy. Keep in mind, that having your process stored in regular tables in many Databases supported by Java, you shall create many kinds of applications, you may use Hibernate for persistence, query and cache as well as JDBC or even Spring helpers. See the following source code to allow this action:

@GET

@Path("/signal/process/{id}/{user}")


@ProduceMime("text/plain")


public
String signalProcess(


@PathParam("id")String
id,


@PathParam("user")String
user) {



JbpmContext ctx =
JbpmConfiguration.getInstance().createJbpmContext();


try{


GraphSession graphSession = ctx.getGraphSession();


ProcessInstance processInstance =
graphSession.loadProcessInstance((
new
Long(id)).longValue());


processInstance.signal();

ctx.save(processInstance);


return
processInstance.getRootToken().getNode().getName();



} catch

(Exception e ) {



e.printStackTrace();



return
"ERROR";



}



finally
{



ctx.close();



}


}






3 – Adding variables to your processes via a simple URL

  • For many reasons, you might need some variables for your processes, maybe for a decision taken or for anything else, so the following source shows how you can get the HttpServletRequest using the injection executed by the REST implementation. This method shows you how you can use contextual http objects, besides your variables from URL.

  • This could be really useful to capture other information, or even process some files not using GET method,
    but the POST method for instance, see the following implementation:

@GET


@Path("/process/{id}/add/var")


@ProduceMime("text/plain")


public
String addVariables(


@PathParam("id")String
id,


@Context
HttpServletRequest request) {



JbpmContext ctx =
JbpmConfiguration.getInstance().createJbpmContext();


try{


GraphSession graphSession = ctx.getGraphSession();


ProcessInstance processInstance =
graphSession.loadProcessInstance((
new
Long(id)).longValue());


Enumeration params = request.getParameterNames();

String param;


StringBuilder b = new StringBuilder();


while
(params.hasMoreElements()) {

param = (String) params.nextElement();


processInstance.getContextInstance().setVariable(param,
request.getParameter(param));


b.append(String.format("Param:%s=%s
is Stored in BPM Context\n"
,param,request.getParameter(param)));

}

ctx.save(processInstance);



return

b.toString();




}
catch
(Exception e ) {



e.printStackTrace();



return
"ERROR";



}



finally
{



ctx.close();



}


}


Time for Testing


As far you can see, everything on our example just returns basic “plain texts” as results, so we canuse those everywhere, in The Developers Conference (A Brazilian Java Conference) I did an examples really “old school”, I used a Borland Delphi 5 client, in terms of integration, I can get an existing Delphi or Visual Basic Application and integrate them with my “Process Server”, than for our Proof of Concept. My process for testing is really easy, as far you can see
in the following image:







This is a simple “Buying Process”, where could be used for many different scenarios, on our case, we try simulate a simple Delphi client interacting with this process. On Delphi's side, I need just a component to interact with HTTP requests
and nothing else, so in my case I used TidHTTP object for it.

My Process Server in Action

When we execute the following URL: http://192.168.161.1:8080/flowlet/start/process/buyticket/edgar , we are informing the process name: buyticket and
the user ir
edgar , and the result we can expect is a text with process id as the text returned via Http, see the following image:






After execute our method, the process instance id is 124, this id might be used for this process interaction, at this moment, my application is used a process which was deployed in my Process Server, and then we can create a new instance from the process called buyticket , so everything is stored in the database, and we can create any kind of
information based on database tables about our process instances,
such as: “Execution time”, “Troubleshooting” and so on.

Now,it's time to see our JBoss jBPM Console in action, take a look on my process listing and you can see the process instance id: 124:







And you can see where in the process, you process instance actually is stopped:






Now, it's time to navigate through the process instance, so I will execute the following rest URL:
http://192.168.161.1:8080/flowlet/signal/process/124/edgar , the result are the following screen shots:







This method, basically execute the signal into the process instance, and move the process to the next node, as far you can in the result and in the following image in the jBPM Console:







Adding the variables based on HttpServletRequest shall be executed using the
following URL:
http://192.168.161.1:8080/flowlet/process/124/add/var?payment=Yes&blog=Edgar
, so based on the Java Web technologies, you can assume that you have 2 variables: payment and blog, so what we wanna do now is to transfer these variables from http context, which are durable just while the server is running or some clustering replication in really durable information stored in the database as process variables. In addition to this capacity, imagine that we need some variable to define some execution path in the process instance handling, like a decision handler based on some expression(EL) based on some variable, for instance:
expression='{payment=="No"}'; this expression can decide in the decision-node “Is Payment Approved?” which path(direction) the process will go as the next execution node and transitions. See the results in the following images:







Now, we can signal the process again, and the results in our jBPM Server could be as the following :









Conclusion

Basically, as far you can see Process Server is something beyond a product, can be a concept that you can apply in many different ways, and one of that, for sure could be using Open-Source technologies, such as we had shown here on this entry.